The use of films for the administration of active agents, such as pharmaceuticals, cosmetic and other materials, is becoming increasingly popular. Such films should have a fairly uniform size, and a substantially uniform distribution of components. The substantially uniform distribution of components is quite important when the films include pharmaceutical components, to ensure accurate dosages.
Films may be formed in any desired fashion, and in some cases it may be useful to form a film on the surface of a substrate. The use of a substrate to form film not only provides ease in processing but may also aid in packaging the film products. Typically, a wet film matrix is deposited onto the surface of a substrate, and then dried to form the resulting film. However, it has been found that traditional methods of forming a film on a substrate are unacceptable, as the wet film matrix has a tendency to “bleed out” the sides, therefore providing non-uniform edges. Non-uniform edges are undesirable since they are not uniform with the center portion of the film, and, in many instances, must be trimmed and discarded, creating wasted product. Attempts to prevent this lack of uniformity include forming films in pre-sized wells, which are very restrictive and do not allow for large-scale bulk processing of films.
The present invention seeks to solve the problems incurred with traditional film processing, such as by providing a method that reduces or altogether eliminates the bleed out problems incurred with other methods.